1. Technical Field
Example embodiments may relate to optical links. Example embodiments may relate to methods of manufacturing optical links. Example embodiments may relate to memory systems having optical links. In example embodiments, optical links may output an optical signal having a uniform size by using a mode coupler.
2. Description of the Related Art
To have an optical link or an optical connection between a memory and a memory controller, a wavelength division multiplexer is generally used.
An arrayed optical waveguide is used to give path difference of an optical signal input to the wavelength division multiplexer. The arrayed optical waveguide occupies a large region in a substrate, and propagation loss occurs in an output optical signal due to the path difference.
That is, in case of a general wavelength division multiplexer, an interference pattern and a shape of an output waveguide mode have a Gaussian shape, so that a frequency response also has a Gaussian shape. When such an optical wavelength divider having a Gaussian frequency response is applied to a system, frequency change of laser diode functioning as a source of the system should be correctly controlled. When the optical wavelength divider is continuously connected in serial and used, it gradually decreases bandwidth of the frequency response, so that it may increase costs of installation and maintenance of the system